1. Field of the Invention
The present invention relates to machining tools, such as cutting tools including table saws.
2. Description of the Related Art
A known table saw is shown in FIG. 9 and is operable to cut a workpiece placed on a table. The table saw includes a turntable 101 that is rotatably mounted on a base 100. An operation lever 105 is attached to the turntable 101, so that an operator can rotate the turntable 101 by means of the operation lever 105. The base 100 has a pair of fixed tables 102 disposed on both sides of the turntable 101 substantially in the diametrical direction. Fences 103 are disposed on the fixed tables 102 in line with each other, so that a workpiece W3 can be placed on the turntable 101 and the fixed tables 102 with one side of the workpiece W3 contacting the fences 103. A vertical vice device 110 is provided on one of the fixed tables 102 and is operable to fix the workpiece W3 in position relative to the fixed tables 102 by applying a downward pressing force against the workpiece W3.
A saw unit 104 (shown partly in FIG. 9) is vertically pivotally mounted on the turntable 101 by means of a support 107. The saw unit 104 has a circular saw blade (not shown) mounted thereon and a motor for driving the saw blade, so that the saw blade can rotate within a plane perpendicular to the turntable 101. The turntable 101 has a plate 106 with a blade intrusion slot that permits the blade to enter the turntable 101 below the upper surface of the turntable 101.
In order to cut the workpiece W3, the operator rotates the turntable 101 in either one of directions indicated by an arrow 120 or 121 to a suitable angular position, so that a cut angle of the workpiece W3 can be determined. The operator then places the workpiece W3 on the turntable 101 such that the workpiece W3 extends between the fixed tables 102 with one side of the workpiece W3 contacting the fences 103 as indicated by chain lines in FIG. 9. In order to cut the workpiece W3 along a cut line (not shown) marked on the workpiece, the operator pushes or pulls the workpiece W3 along the fences 103 as indicated by an arrow 122 or 123 so as to register the cut line with the saw blade. Then, the operator operates the vice device 110 so as to fix the workpiece W3 in position relative to the fixed tables 102 and the turntable 103. As a result, the workpiece W3 can be cut along the cut line when the saw unit 104 moves downward.
With the known table saw, the adjustment of position of the workpiece W3 must be performed by directly manually moving the workpiece along the fences. Therefore, it is difficult to make fine adjustments to the position of the workpiece. W3. In addition, the adjustment work is time consuming.
It is, accordingly, one object of the present invention to teach improved machining tools, in which the positional adjustment of a workpiece can he easily quickly performed.
According to a first aspect of the present invention, a machining tool is taught that includes a table for placing a workpiece thereon, and a fixing device for fixing the workpiece in position relative to the table. The fixing device may be operable in a first node for fixing and releasing the workpiece relative to the table and in a second mode for shifting the workpiece relative to the table. In such a design, the position of the workpiece can be adjusted by operating the fixing device in the second mode, and the workpiece can be fixed in the adjusted position by operating the fixing device in the first mode. As a result, the adjustment of the position of the workpiece can be quickly and reliably performed in comparison with the direct manual adjusting operation of the workpiece.
Preferably, the fixing device is a vice device that can press the workpiece against an abutting member such as a fence. The vice device may have a shaft that is adapted to be rotated about its axis in the first mode and that is adapted to be pivoted within a horizontal plane about a pivotal axis in the second mode.
The shaft of the vice device may have a pad for contacting the workpiece. In the second mode, with the pad pressed against the workpiece to produce an appropriate frictional force between the pad and the workpiece, the shaft may be shifted to move the workpiece along the fence.
Preferably, the pad is movable relative to the shaft in the axial direction of the shaft, and a biasing member is provided between one end of the shaft and the pad so as to resiliently bias the pad toward the workpiece. As a result, during the pivotal movement of the workpiece, an appropriate frictional force may be maintained between the pad and the workpiece, and the pad may reliably contact the workpiece.
According to a second aspect of the present invention, a machining tool is taught that includes a table for placing a workpiece thereon, a base for movably supporting the table, and a shifting device operable in a first mode for fixing and releasing the table relative to the base and operable in a second mode for shifting the table relative to the base. In such a design, with the workpiece placed on the table, the table may be moved relative to base in the second mode of the shifting device. When the workpiece has reached a desired position, the table and the workpiece placed thereon can be fixed in position in the first mode of the shifting device.
Preferably, the shifting device includes an operation member that has a shaft. In the first mode, the shaft may be moved in the axial direction. In the second mode, the shaft may be pivoted about a first axis that extends perpendicular to the axial direction.
Other objects, features and advantages of the present invention will he readily understood after reading the following detailed description together with the accompanying drawings and the claims.